Hi guys, I have a Scott Addict Disc 30 2019 (Endurance Geometry). The bike came with the Schwalbe Durano 700 x 32C, which I believe it’s intended to give some more comfort, durability, etc… The thing is, I just can’t go fast with this bike. I’ve added some aerobars in to it but even so, I’m not going that fast and thought that it may be caused by the tires. So, before I go out and spend some cash on new ones, I would like to know your thoughts on it: In your experience, does the tire size influences that much? What would be the increment of speed (in same conditions of temperature, pressure, wind, power, etc.) changing just the tires to, let’s say the classic 700x25C? I’ve searched for some calculators in the internet but had no success. Thank you all!
Clinchers with inner tubes? Convert to tubeless first before thinking about a narrower tire.
Hey there,
there may be a few things going on. So maybe you have a new position on the bike and you’re not yet comfortable with it or the fit you have on it compromises your power development a bit unbeknownst to you.
But I do think that yes, also your tires are a main culprit. Not necessarily the dimension. Also not the brand but rather the model. While I never rode a Durano these are known to be just dead ducks on the water. They may be durable (I guess hence the name) but they have a reputation to just roll awful.
This is also quantified by https://www.bicyclerollingresistance.com/road-bike-reviews
Just look them up. They are way at the bottom with around double the watts resistance than the top tires. According to this you loose around 20 watts compared to running, say, Conti GP 5000 or Schwalbe Pro One.
i totally agree with reviewing the comparison that Frank offered. i fully endorse the GP 5000. but also want to ask. are you running the same air pressure in your schwalbe 32C as you were in narrower tires?
Hi guys. Thank you all for the answers.
I had a argon bike before the scott. Back then I was using the 700 x 23C with 8 bar. It was much faster then my actual setup. That’s why the question came up.
You say it’s endurance fit, how did the Argon compare geometry-wise? The point being - your body provides the most aerodynamic drag and if you are sitting more upright on this bike that will have a greater impact than tyre choice
On my Canyon RoadLite, 2 years ago, I switched the tires from 28mm to 38mm to convert it to “gravel mode” 
One day, I tried to improve my time on a local climb, I pushed an average power higher by a couple watts compared to my previous PR and my time was… worse by one full minute (on a 16 min. climb). So, yeah, there might be an effect on the speed, depending on the width of your tires !